Introduction Conclusions References

Increases in the growth rate of plants and microbes in the Mojave Desert in response to predicted increases in precipitation and CO2 due to global climate change may induce nutrient limitations. This study was designed to measure the pool of potentially bioavailable nutrients in soils of the Mojave Desert. Soils were collected from shrub and interspace microsites and then subjected to amendment...

A bell-shaped vertical profile of chlorophyll a (Chl a) concentration, conventionally referred to as a subsurface chlorophyll maximum (SCM) phenomenon, has frequently been observed in stratified oceans and lakes. This profile is assumed to be a general Gaussian distribution in this study. By substituting the general Gaussian function into ecosystem dynamical equations, the steady-state solution...

Silicon is reported to reduce the toxic effects of Al on root elongation but the in planta mechanism by which this occurs remains unclear. Using seedlings of soybean (Glycine max) and sorghum (Sorghum bicolor), we examined the effect of up to 2 mM Si on root elongation rate (RER) in Al-toxic nutrient solutions. Synchrotron-based low energy X-ray fluorescence (LEXRF) was then used for the in sit...

A system of nonlinear partial differential equations is proposed as a model for the growth of an avascular-tumour spheroid. The model assumes a continuum of cells in two states, living or dead, and, depending on the concentration of a generic nutrient, the live cells may reproduce (expanding the tumour) or die (causing contraction). These volume changes resulting from cell birth and death gener...

C57BL/6J (B6) mice consume more sugar and fat solutions than do 129 mice in 24-h preference tests. Previous studies have attributed this observation to strain differences in taste responsiveness to these nutrients. We tested the hypothesis that differences in postingestive responsiveness contribute to the strain differences. In experiment 1, B6 and 129 mice were trained to associate consumption...

In 1976, a method of growing lettuce and other leafy vegetables on a floating raft of expanded plastic was developed independently by researchers at the University of Arizona and the University of Pisa in Italy. Today facilities exist in a number of countries including the United States, Japan and Canada. Termed “Deep Flow Hydroponics,” the system consists of horizontal, rectangular shaped tank...

TRELEASE and TRELEASE (2) have called attention to the advantages, froln the standpoint of pH control, of using mixtures of aimmiiionliumii and nitrate salts in making up nutrient solutions. Sulphuric acid is customarily employed as a means of adjusting the pH of solutions during an experiiiient. The purpose of this paper is to call attention to the advantages of using nitric acid as a means of...